Why is it that everybody wants to connect this wire to the Ignition Coil's 12V power supply, instead of finding a proper 12V switched source?

Whats the reasoning behind that?

 

Thats not rignt??? I used it to power all three of my MSDs

 

i think its just easy for people, they're already running IGN wires over there, so they tap into the acc. power while they're at it.

I did mine a little different though, all independant power for the ECU through a hidden anti theft switch but I can see why they'd do it - as Allen said, doesn't that work?

 

Got me, Claudio. I splice it w/ the green Ignition Switched Wire and send it either to the factory wiring harness' +12VDC IGN or directly to the main ignition relay.

 

Its not that its incorrect, im just wondering whats the reason for it, apart from the fact that it is a switched power source. Oh, and you should probably upgrade the fuse for the ignition system, those 3 boxes do tax some current load from that circuit.

But depending on the vehicle, application and how you're running the car, ie, street, track, road race, fully gutted, new electrical system, i would preferably run that wire to the ignition switch, i dont know, i guess its just me being paranoid about going to main relay power on the ignition system, when there's 12v switched wires inside the cockpit. And if its a fully gutted track car, then it gets its own on/off switch on a dashboard, just like everything else.

I was just curious to see people's thought on the matter, since i do get a lot of comments about that very thing often.